Portable percussive tool



Patented Feb. 17, 1931 i n.' RRNRDICT, or cOsCOB, CONNECTICUT, VAssIGfNOR To CHTOAGO PNEUMATIC earns-T vOrmes j TOOL oeMrANY, OF NnwvYORK, N. Y., A CORPORATION or NEW JERSEY PORTABLE rnRoUssrvn TOOLApplication led April 5, 1928'. Serial No. 267,624.

rl`his inventionr relates toportable` power operated percussive toolsadapted to be manually supported and directed rto. the work. lt haspractical application to tools for hand drilling and demolition workgenerally.

. @ne Cbject of theinvention is-to provide improved means for relievingthe operatorv of the sho-ok and reactionof vthe tool when in operation.Another Object is to protect the tool against the destructive eects ofvibration. Another object is to support and to control the operation ofthepercussivefmotor of such a tool in an improved manner. Other objectswill be apparent from the detailed description which follows.:

ln order toillustrate the invention one concrete embodiment thereof is4shown in the accompanying drawings in which:

Fig. 1 is a vertical sectional view showing a portion of thepercussive'motorin elevation, the latter being in its retracted lor nonoperativeposition;A and Fig. 2 is a viewsimilar to Fig. 1 showing themotor in running position. A g

The invention comprises a. member3 generally cylindrical in `formproviding an elon-` gate chamber 3e in which is slidablyA mounted apercussive motor A adapted-to impart its blows to a drill steel or otherworking tool B which extends into the forward or barrel end of motor A.Cylinder member 3 isf arranged to be manually supported 4and oontrolledby one or more handles 4, which may be integral with or secured tomember 3. In the present instance the handles form portions of a T heador rearward extension 5 secured to member 3 in any suitable manner' asby bolts (not shown). Backhead 5 is hollow and forms a portion of thechamber 3a in which motor A moves, a bearing ring (i and suitablepacking' means being provided be` 'tween backhead 5 and cylinder 3 for apure pose presently to be described. The admis-y ranged to ent-er therearward or handle por-V tion of chamberV 3a.

Motor A has a head slidablytting the has suitable packing means at 16and controls one orinore radial ports 17 extending through the wall ofcylinder member 3., The rearward portion of head 10 is reduced indiameter and communicatesv freely with the space between the head 10 andbearingring 6.V

Motor A and supporting cylinder 3 cooperate to divide the elongatechamber 3a of the latter into three distinct parts or chambers, whichvary inysize with the'movement of motor A. Thethree parts comprise. the

live air .port or chamber rearwardly of bear@ ing ring 6 and into whichmotor extension 11 extends, the intermediate or exhaust chamber betweenthe head 10 and bearing ring 6 which communicates with atmospherethrough ports 17 when the mot-or moves to the position` shown in Fig. 2,and the cushion chamber provided between motor head 10 and packing ring13.` The opposed pressure areas of motor A provided by extension 11(which is subjected to pressure in the live air chamber) on the onevhand and by the forward face of head 10 on the other (which issubjected to thepressure in the cushion chamber) are differential insize, the area presented by extension 11 being somewhat Ythe larger sothat when throttle valve 8 is open the pressure of the admitted motiveiiuid operates to move motor A` forwardly. Extension 11 has an axialbore as indicated which serves to conduct a portion of the pressurefluid in the live air chamber to the percussive motor to operate thesame.

Motor A may be of any suitable or desired type. As shown, it comprises ahammer piston 18 whose reciprocations are controlled by an automaticpressure thrown sleeve valve 19 disposed in VaV valve box 20 providedwith a lidZl, .the Valve parte bei-ugidiSpQSfl Within' .roo

head and securely held in place by extension 11. The exhaust of themotor is discharged into the annular chamber produced by the reducedrearward portion of head 10.

In order to cushion the forward movement of motor A and to returnthe'motor to its rearward or inoperative position (Fig. 1), means areprovided for admit-ting a charge of pressure liuid to the cushionchamber provided between head 10 and packing ring 18. By preference onecharge is admitted to the cushion chamber when the tool is started andanother charge is directed thereto when the tool is stopped, there beingno supply of fluid to thel cushion chamber while the tool continues inoperation. rl`he preferred arrangement includes a passage 22 in cylinder3 which opens into the cushion chamber on the one hand through a port22a and terminates in a port 22o adjacent the fluid pressure inlet ofthe tool. VPort 22?) is controlled by the head of a plunger 23 which bypreference takes the form of an extension on throttle valve 8. Adjacentthe head of extension or plunger 23 is an annular groove 24 otsutlicient width to admit a charge of pressure fluid to passage 22 whenthe throttle valve moves from the closed position shown in Fig. 1 to theopen position shown in Fig. 2, and another charge when the throttlevalve moves back to closed position. 1n either the fully closed or fullyopened position of the valve, port 22?) is cut olif by plunger 23 fromcommunication with the motive fluid inlet. Accordingly, when theoperator actuates lever 9 to open throttle valve 8, a charge of pressurefluid goes through passage 2Q to the lcushion chamber, which charge iscompressed by the forward movement of motor A due to the proportionatelygreater area of extension 11 which is subjected to the live motivefluid. The forward movement of motor A continues until the edectivepressure in the live air chamber is equalized by the effective pressurein the cushion chamber. Motor A goes into operation as soon as theadvancing movement of the motor places ports 17 in communication withthe exhaust portion of chamber 3a (Fig. 2). The ruiming position ofmotor A in cylinder 3 is determined to a certain extent by the pressureapplied by the operator to handles Ll, which pressure assists theeffective pressure in the cushion chamber in balancing thepreponderating pressure which tends to move the motor forwardly incylinder 3. wWhen the operator closes the throttle valve a second chargeof fluid is admitted to the cushion chamber, as previously described,and the pressure therein operates to move motor A rearwardly as thepressure in the live air chamber escapes through the motor to theexhaust chamber and thence to atmosphere through ports 17, the rearwardmovement of the motor continuing until the ports 17 are closed ott byhead l0 whereupon the motor comes to rest in the position shown in Fig.1.

The working tool B is arranged to be retained in operative relation withpercussive motor A without interfering with the movement of the motor incylinder 3, the retaining means being connected to a rigid portion oi'the tool so that the operator can conveniently withdraw the tool andshift it to a new location. To secure a rigid connection and yet topermit the use o1Q a` retainer of minimum length, gland nut is providedwith an enlarged extension 15a, which encloses and protects theprojecting end ot motor A when the latter is in its retracted orinoperative position (Fig. 1). rlhe retainer is secured` to theextension 15a and in the present instance is in the form of a yoke 25,which cooperates with the collar on the shank of the working tool. Yoke25 has inturned ends 25a extending into suitable sockets in entension15a, this pivotal connection enabling the retainer to be swung to oneside when the working tool B is to be removed or inserted in the Jtool.j

lll/'bile a preterred'form of the invention has been herein shown anddescribed, it is to be understood that the invention is not limited tothe specific details thereof, but covers all changes, modifications andadaptations within the scope ot the appended claims.

l claim as my invention:

1. A fluid pressure tool comprising a member providing an elongatechamber, a handle on said member for manually support-ing the latter, atluid pressure percussive motor movable as a unit in said chamber, andmeans on said member and said motor cooperating to provide opposingpressure chambers and an intermediate exhaust chamber, and means fortrapping pressure fluid in one of said pressure chambers.

2. A fluid pressure tool comprising a member providing an elongatechamber with an open end, a handle on said member for manuallysupporting the latter, means for restricting a portionv ot said chamberremote from said open end, and a percus-:sive motor movable as a unit insaid chamber and having a part projecting through said open end and anextension in said restricted portion.

3. A fluid pressure tool comprising a member providing an elongatechamber open at one end and closed at the other, a handle on said memberfor manually supporting the latter, means for restricting a portion ofsaid chamber adjacent the closed end of the saine, a percussive motormovable as a unit in said chamber and having a part projecting throughsaid open end and an extension in said restricted portion, saidextension serving as a conduit for supplying pressure liu'd to saidmotor.

il. A fluid pressure tool .comprising a cylinder member providing anelongate chammost part of'said chamber,said member liavslidably fittingsaid chamber beyond saidring, an extension on said motorrslidablyfitting said bearing ring and pro]ecting with? 1n the rearmost part ofsaidchamber, said member havingvent ports controlled by said head andarranged on forward movement of said motor to connect the portion of thechamber between said head and said ring to atmosphere.

5. A fluid pressure toolcomprising acyl-V inder member providing anelongate chamber having a closed end, a fluid pressure Vinotor movablewithin'said chamber, cooperating means on said member and said motorvfor dividing said chamber into three parts which vary in size withthemovement of said motor, said means including a bearing ring withinsaid chamber in spaced relation to theclosed end thereof and a head onsaid motor slidably fitting said chamber beyond said head, an extensionon said motor slidably fitting said bearing ring and projectinglwithinthe rearing vent ports controlled by said head and arranged onforward movement, of said mo'- torto connect the portion of the chamberbe-v tween said head and said ring to atmosphere, said motor having abarrel extending beyond said cylinder member, packing and bearing meanson saidV cylinder for said barrel defining a cushion chamber between thesame and said head, and means for supplying a chargev of pressure fluidto said cushion chamber -to move said motor rearwardly or to resist itsforward movement. y

6. A fluid pressure tool comprising' a cylinder member providing anelongate chamber, a fluid pressure motor movable within said chamber,cooperating means on said member and said motor for dividing saidchamber into three parts, namely, a live air chamber, an exhaustchamber, and a cushion chamber, the relative sizes of said chambersbeing varied by the movement of said motor, means for admitting pressurefluid to said live air chamber and for conducting a portion thereof tosaid motor to operate Vthe latter, and means for supplying a charge ofpressure fluid to said cushion chamber.

7. A fluid pressure tool comprisingl a handle member providing anelongate chamber, a fluid pressure percussive'motor mounted for slidingmovement in said chamber, means for controlling the position of saidmotor within said chamber by pressure fluid including opposed areas onsaid motor, and

means operating automatically for directing a charge ofpressure fluidtofone ofsaid areas when the toolis started-and for shutting ofi1further supplyjto said area while `thetool is in-operation.

f8; A fluidpressure tool comprising ahan-"i dle member-providing anelongateV chamber,

arfluid ypressure percussive motor mounted fori sliding movement in saidchamber, means for controlling the position of said `motor within saidchamber by pressure fluid includingopposed areason said motor, and meansoperating automatically to direct a charge of; pressure fluid to one ofsaid areas only-.at the starting and stopping of'saidtool. i

9; Aifluid pressure tool comprising a han-` dle memberfproviding'anelongate chamber, a

fluid pressure percus'sive motor mounted` for Y slidingi movement insaidchamber' and havingvopp'osed areas, means for controlling the sposition of said motor, and meansfor directing acharge ofpressure fluidto one of said areas when the pressure fluid is admitted to.`

saidA motor to provide a resilient cushion for said motor and' again,-when the supply i of pressure fluid is cut off, in order to move saidmotor to its rearmost position" within said member. 1 i l0. A liuidpressure tool comprising a mem-` ber providinglan elongate chamber,means for y controlling I the admission of pressure fluid'f to saidchamber includinga throttleV valve, ajfluid pressure motormovablyinount-- ed in said chamber'and presenting a pressure area to theadmitted motive `fluid and. pro viding an opposing pressure Varea ofsmall eX- tent, and means operating automatically only when said valveis opened or closed for ad# mittingla 'charge of pressure liuid torsaidsmaller area. Y i

11. A fluid pressure tool comprising a member providing an elongatechamber, means for controlling the admission of pressure fluid to saidchamber includinga throttle valve, a fluid pressure motor movablymounted in s aid chamber and presenting a pressure area tothe admittedmotive fluid and providing an opposing pressure area of small eX- tent,and meansy controlled by said throttle valve for admitting a charge ofpressure fluid to said smaller area momentarily during the openingmovement of said valve.

12. A fluid' pressure tool comprising a member providing an elongatechamber, means for controlling the admission of pressure fluid'to saidchamber including a throtw tle valve, a fluid pressure motor movablymounted in said chamber and presenting a pressure area to YtheA admittedmotive fluid and providing an opposing pressure area of smaller extent,`and means associated with said throttle valve for directing pressurefluid momentarily to said smaller area at the opening and closing ofsaid valve.

13. A fluid pressure tool comprising a member providing an elongatechamber,

means for controlling the admission of pressure Huid to said chamberincluding a throttle valve, a fluid pressure motor movably mounted insaid chamber and presenting a 5' pressure area to the admitted motiveHuid and providing an opposing pressure area of smaller extent, andmeans for admitting a charge of pressure fluid to said smaller area.when said throttle valve is opened, said lastf lo Vnamed meanscomprising an extension on said valve and a passage in said memberleading to said smaller area and controlled by said extension.

14. A fluid pressure tool comprising a member providing an elongatechamber,

means for controlling the admission of pressure fluid to said chamberincluding a throttle valve, a fluid pressure motor movably mounted insaid chamber and presenting a pressure area to the admitted motive fluidand providing an opposing pressure area of smaller extent, and meansassociated With said throttle valve for directing pressure fluidmomentarily to said smaller area at the opening and closing of saidvalve, said last-named means comprising a plunger having a reducedportion actuated b v said valve and a passage in said member leading tosaid smaller area, said passage receiving pressure fluid by the reducedportion of said plunger during the movement of the latter in eitherdirection.

15. A fluid pressure tool comprising a cylinder member having a handleand providing an elongate chamber, a fluid pressure percus-sive motormovable Within said chamber and projecting therebeyond, packing, andbearing means on said member for the projecting portion of said motorincluding a gland nut, a Working tool extending Within said motor toreceive the blows thereof, and means on said gland nut for retainingsaid Working tool in operative relation With said motor Withoutinterfering With the movement of the latter in said member.

16. A fluid pressure tool comprising a cylinder member having a handleand providing an elongate chamber, a fluid pressure percussive motormovable Within said chamber and projecting therebeyond, packing andbearing means on' said member for the projecting portion of said motorincluding a gland nut, a Working tool extending Within said motor toreceive the blows thereof, and a retainer lvolie on said gland nut forretaining said Working tool in operation relative to said motor Withoutinterfering with the movement of the latter in said member.

Signed by me at Coscob, in the county of Fairfield and State ofConnecticut, this 4th day of April, 1928.

WILLIAM H. BENEDICT.

BIE

